Form tie for concrete structures



arch J. B. HAWLEY, JR

FORM TIE FOR CONCRETE STRUCTURES Filed March 13. 1926 Patented Mar; 81927.

UNI'TED' STATES V 1,619,933 PATENT OFFICE.

JOHN B. nAwLnY, an, .or Mmnnnroms, MINNESOTA, assrenon 'ro HAWLEY1nvnnzrrens, INCORPORATED, or MINNEAPOLIS, mmnnsorn, A conroan'rxon orDELAWARE.

FORM TIE FOR CONCRETE STRUCTURES.

Application filed March 13, 1926. Serial m. 94,458.

Thisinvention has to do with an'improved tie for tying together theforms used for molding monolithic structures such as concrete walls etc.In the past there have been provided struts which are so arranged as toretain the form Walls properly separated, but such devices have not beenof proper nature or shape or provision to allow them to project throughthe form walls 'themselves. As a consequem it has either been necessaryto provide relatively large openings in the walls of the form to allowthe strut to pass through. One of the objects of the present inventionis to provide a form tie consisting of a metal strip which is so shapedin itscross section as to give it ample stiifness to retain the sides ofthe form in the proper condition of separation, and at the same time isof such a nature that it can be flattened out at the points where itpasses through the walls of the form. This will allow the end portionsof the tie strip to be passed through the walls between the partsthereof and without the necessity of providing special holes for theaccommodation of the ends of the tie.

Another feature ofthe invention relates to the provision of a continuousstrip of material of the. desired cross section and made of the propermetal and properly heat treated so that when it is to be used it can becut off into sections of the desired length. The end portions of thesesections may then be flattened out so asto allow them to ass easilybetween the boards of the walls 0 the form. This will make it possibleto secure the necessary stillness of the tie strip at all points betweenthe inner faces of the walls, and at the same time will make it possibleto flatten out the end portions of the tie so as to allow .it to passeasily between the boards of the walls.

Another feature'of the invention relates to the provision of a tie stripwhich can be easily secured to the walls of the form by nails, screws orother suitable attaching devices. This result may be accomplished byperforating the strip uniformly throughout its length with perforationswhich are relatively close-together; or this result may be secured bymaking the strip of a material.

which is relatively soft and of such thickness that the nails may bereadily driven through it into the form even when especially perforated.

Another feature of .the invention relates to the provision of a form tiestrip of such a nature that its end portions can be easily bent aroundthe beams or joists of the form walls, being also nailed or screwed tothe same. in this way the attachment of the walls will be still furtherreinforced and the danger of pulling out the nail holes will be stillfurther reduced.

Other objects and uses of the invention 35 will appear from a detaileddescription of the same which consists in the features of constructionand combination of parts hereinafter described and claimed.

In the drawing Fi 1 shows a perspective view of a section t rough a pairof form walls joined and retained together by tie strips embodying thefeatures of the present invention; 'Fig. 2 shows afragmentary-perspectivecross section through a section of channel stripsuch as is illustrated in Fig. 1;

the strip is not Fig. 3 shows a view similar to that of Fig. 2,

but illustrates a modified form of section comprising a 2 bar; Fig. 4shows a section similar to that of Fig. 2, but illustrates a roundedchannel having flat side flanges; Fig. 5 shows a section similar to thatof- Fig. 2, but illustrates a rectangular channel section; Fig. 6 showsa view similar to that of Fig. 2, but illustrates an angle section 35with one of the. arms longer than the other: and Fig. 7 shows a viewsimilar. to that of Fig. 2, but illustrates an angle section with .thearms of equal length.

'preierably other than a flat strip so as to giveit the necessaryrigidity and stlfiness-to sufliciently withstand any tendency of thewalls 8 and 9 to fall together. In this connection it must be rememberedthat where the walls are separated a considerable distance apart, as isthe case in the molding of relatively thick structures, the collapsingtendency of the tie under pressure increases substantially as the cubeof the distance which the walls 8 and 9 are separated from each other.

It is desired that the end portions of the tie should be able to passthrough cracks between the boards of the walls of the form. For thispurpose the end portions of the tie strips should be flattened out.Nevertheless it is desirable to provide the tie strip as a continuousstrip of uniform section and of such material and anneal as to allow theend portions of the tie to be flattened out. This will make it possibleto cut off desired lengths of the tie strip, and will make it possibleto flatten out the end portions of eacl of these lengths just beforethey-are use Preferably the tie strip is made of relatively soft metalsuch as soft annealed steel, and 1s rolled out in strips of the desiredcross section. At the same time these strips are preferably punched orotherwise perforated at points re atively close together along thecentral line.

When asection of such a stri is cut off its end portions 17 and 18 may eflattened out so as to pass through the cracks 19 and 20 between boardsof-the walls 8 and 9, thus making it possible to set the tie strip intoplace without having to provide special openings in the walls of theform.

It will be noted from examination of Figure 1 that the tie strip is of.the curved or angular section at substantially all points between theinner faces of the walls,8 and 9 so as to maintain the full stifinessnecessary to hold said walls under proper separation.

At the same time byflattening out the ends of the strip the are readilypassed between the boards as already explained. 7

Examination of Figure 1 also shows that the end portions 17 and 18 maybe easily opened over the struts '13 and 14; or that said end portionsmay be given an additional twist so that they may be laid flat againstthe surfaces of the beams 11 and 12. This illustrates the great range ofusefulness of this type of device.

When the stripis initially punched the end portions thereof can besecured as by the use of nails or the like 21; but in the absence ofsuch punching it is possible to drive the nails directly through thematerial of the strip on account of the fact that said strip isrelatively soft and annealed.

It is deemed unnecessary to comment especially upon the different formsillustrated in'Figs. 2 to 7 inclusive; beyond calling attention to thefact that if desired the perforations may be left out and the strip beunperforated as shown in Fig. 7. v

'While I have herein shown and described only certain embodimentsof thefeatures of my present invention, still I do not intend to limit) myselfto the same except as I may do so in the claim.

I claim:

In combination spaced apart concrete forms, and means for maintainlnsaid forms a desired distance apart comprising a relatively thin stripof metal having a non flat cross section to provide stiffness inbrac- 1nthe forms, the metal being of a malleab e nature and flattened at spacedortions wherever desired for the purpose 0 fitting between adjacent formsections.

JOHN B. HAWLEY, JR.

